Code detecting means



y 1946- F. NICHOLSON 2,403,744

CODE DETECTING MEANS Filed March 16, 1945 H m B H w 1; w w Q L m B 7 kfi I Ffi. W m E M l .3 E

I/YVENTOR.

flan/z 1E? Me/zolson. BY 2 i HIS ATTORNEY 1 Fly 2 Patented July 9, 1946CODE DETECTING MEANS Frank H. Nicholson,

County,

of Pennsylvania Penn Township, Pa., assignor to The Union SignalCompany, Swissvale,

Allegheny Switch & Pa., a corporation Application March 16, 1945, SerialNo. 583,058

6 Claims.

My invention relates to coded signaling apparatus and particularly toimproved means for detecting coding operation of a code following relay.

An object of my invention is to provide code detecting means which isimmune to false response in the event the contacts of the code followingrelay are defective or out of adjustment.

A further object of this invention is to provide all-relay codedetecting means which is arranged so that fused or overlapping contacton the code following relay cannot result in improper energization ofthe associated code detecting relays.

Other objects of the invention and features of novelty will be apparentfrom the following de scription taken in connection with theaccompanying drawing.

I shall describe two forms of code detecting means embodying myinvention and shall then point out the novel features thereof in claims.

In practicing my invention, I provide the code following relay with twomovable contacts which are operated between a first and a secondposition substantially in synchronism. These movable contacts areconnected by a supply conductor and one contact connects the supplyconductor to one or the other terminal of a source according as thecontact is in its first or its second position. The othe movable contactwhen in one position establishes connection from the supply conductorthrough the winding of a first auxiliary or code detecting relay to aterminal of the source, and in its other position establishes connectionfrom said supply conductor through the winding of a second auxiliary orcode detecting' relay to a terminal of the source providing the contactsof the first auxiliary relay are picked up. The circuits are arranged sothat overlapping of the contacts of one of the movable contacts on thecode following relay results in short-circuiting of the battery withresultant deenergization of both auxiliary relays, while overlapping ofthe contacts of the other movable contact on the code following relayresults in short circuiting of one or the other of the auxiliary relays.

In the drawing:

Fig. 1 is a diagramof a section of railway track equipped with codedtrack circuit apparatus and provided with means embodying my inventionfor detecting code following operation of the track relay, and

Fig. 2is a diagram showing a, modified arrangement adapted for use wherecode following operation of one or the other of two code following trackrelays is to be detected.

Similar reference'characters refer to similar parts in each of the twoviews. I

In most instances in the drawing relay con.- tacts are shown directlyunder the relay winding, but in some cases in order to simplify thedrawing relay contacts are separated from the relay winding and wherethis is done the relay with which the contact is associated isdesignated by an appropriate reference character placed directly overthe contact.

Referring to Fig. l of the accompanying drawing, there is shown thereina section of railway track having track rails I and 2 which areseparated from the rails of adjacent sections by insulated joint 3.Trafiic in this section normally moves in the direction indicated by thearrow, that is, from left to right, and a wayside signal S is located atthe entrance end of the section and governs traffic in the section. Asshown, the signal S is of the color light type and has a red or stoplamp R and a green or clear lamp G.

A code following track relay TR is connected across the section rails atthe entrance endof the section and is operated by master code energysupplied over the section rails from the track battery TB at the exitend of the section. The supply of energy from the track battery to thesection rails is controlled by a coding device CT which has a contact Inwhich is operated between an open and a closed position at a selectedrate, such as to times a minute.

The track relay TR governs the supply of energy to slow releaseauxiliary relay FSA and BSA from a battery [2, while the relay BSAgoverns the supply of energy to the lamps of the signal S.

When the track section is vacant, energy supplied from the battery TBduring the closed periods of contact ID of coding device CT feeds overthe section rails to the Winding of the track relay TR and picks up thecontacts of this relay, while during' the open periods of contact I!) ofthe coding device CT the supply of energy from battery TB to relay TR isinterrupted and the contacts of the relay TR release.

The track relay TR is equipped with a first movable contact l4 and asecond movable contact I6 which are connected by asupply conductor IS.The track relay contacts are biased to a released or first position andare movable therefrom to a picked-up or second position.

When the track relay contacts are in their picked-up or second position,energy is supplied from the second or positive terminal of the batteryI! over front contact I4 of relay TR, supply conductor l5, front contactl6 of relay TR and winding of relay FSA to the first or negativeterminal of the battery l2. The energy supplied to relay FSA picks upthe relay contact with the result, that during the released periods ofthe track relay TR energy is supplied from, the second or positiveterminal of the battery through the winding of relay BSA, front contactll of relay FSA, back contact "5 of relay TR, wire l5, and back contactH of relay TR to the negative or first terminal of the battery l2.Accordingly, contact l8 of relay BSA is picked up and estab lishes thecircuit of the green lamp G of the si nal S. The relays FSA and BSA areof a type the contacts of which are slow to release and the contacts ofthese relays remain picked up during the intervals in which the supplyof energy to the relay winding is interrupted.

When a train enters the section, the contacts of relay TR remainreleased and do not establish the circuit of relay FSA and, after ashort time interval, contact 11 of relay FSA releases and interrupts thecircuit of relay BSA and its contact l8 releases to interrupt thecircuit of the green lamp G and establish the circuit of the red lamp R.When the section is vacated, the track relay again responds to codedenergy and energy is supplied to relay FSA during the pickedup periodsof the track relay contacts and is supplied to the relay BSA during thereleased periods of the track relay contacts so that the circuit of thegreen lamp of signal S is established.

The circuits of the relays FSA and BSA are arranged so that fusing oroverlapping of the front and back points of contacts l4 and it of thetrack relay TR cannot result in improper energization of relay BSA withconsequent display by the signal S of a green instead of a redindication.

As explained above, when the section is occupied, the contacts of relayTR are released and should interrupt the circuit of relay FSA so thatits contact ll interrupts the circuit of relay BSA and thus causescontact l3 of relay BSA to be released and maintain the circuit of thered lamp of the signal S.

If, for any reason, the movable contact It of the 'track relay TRsimultaneously engages its front and back points of contact, aconnection will be established between the two terminals of the batteryl2 and the battery will be short circuited but energy will not beimproperly supplied to relays FSA and BSA and they will remain releasedand maintain the circuit of the red lamp R of signal S.

If the movable contact it of relay TR simultaneously engages its frontand back points of contact, and the contact M of relay TR engages itsfront contact, the relay FSA will be energized, but the relay BSA willbe shunted over the circuit which is traced from the left-hand terminalof the relay winding over front contact ll of relay FSA, back contact l6of relay TR, wire l5, and front contact l4 of relay TR to the righthandterminal of the winding of relay BSA. As the winding of relay BSA isshunted the relay contact I8 is released and maintains the circuit ofthe red lamp of the signal S.

Furthermore, under the conditions stated above, the relay BSA not onlyis shunted, but no circuit is established to supply energy to the relaywinding and the relay contact is certain to remain released.

Similarly, if the movable contact I6 of relay TR simultaneously engagesits front and back points of contact and contact l4 engages its backcontact, the relay FSA will be shunted over the circuit which is tracedfrom the left-hand terminal of the relay winding over front contact l6of relay TR, wire l5, and back contact IA of relay TR to the right-handterminal of the winding of relay FSA. As the winding of relay FSA isshort circuited, the relay contact I! will be released and willinterrupt the circuit of relay BSA and thus insure that contact l8 ofrelay BSA is released and causes signal S to display its stopindication.

In addition, under these conditions, a circuit is not established forsupplying energy from the battery l2 to the relay FSA and its contact I1is certain to remain released.

front contact 16 of relay TR fuses and remains closed, and if at thesame time back contact I4 of relay TR fuses, the relay FSA will be shortcircuited over an obvious circuit and will remain released.

Likewise, if back contact is and front contact ll of relay TR fuse andremain closed, the relay BSA will be short circuited over the circuitcontrolled by front contact ll of relay FSA if relay FSA is picked up,but under these circumstances relay FSA will ordinarily be releasedbecause of the open front contact I6 of track relay TR. In any caserelay BSA will be released and maintain the display of the stopindication by signal S.

Since bridging or overlapping contacts on the track relay TR cannotresult in improper energization of the relay BSA, there is nopossibility that the relay BSA will be picked up unless the relay TR isresponding to coded energy. Accordingly, at times when the relay TR isnot responding to coded energy, as for example, when the section isoccupied or the supply of coded energy over the section rails is cut offfor any other reason, or if steady energy is supplied to the trackrelay, the relay BSA is. certain to remain released and maintain thedisplay of the stop indication b signal S, and there is no possibilitythat the relay BSA will be improperly picked up to cause signal S todisplay its green indication.

The principle embodied in the equipment shown in Fig. 1 is alsoapplicable to situations where two track relays are employed and thereis decoding means governed jointly by these relays. One example of sucha situation is at an intermediate signal location in single trackstretches where traffic is operated in one direction at times and in theother direction at other times.

In Fig. 2 of the drawing there is shown a portion of the equipment at anintermediate signal location. In order to simplify the disclosure, onlythe equipment essential to the understanding of this invention has beenillustrated and the remainder of the equipment may be arranged in anyappropriate manner, as, for example, as shown in Fig. 10 or 1d ofLetters Patent of the United States No. 2,344,573 issued March 21, 1944,to J. J. Van Horn, or in Fig. 1c of Letters Patent of the United StatesNo. 2,344,333 issued March 14, 1944, to J. J. Van Horn.

As explained in the above-identified Van Horn patents, the equipment forthe track stretch is controlled so that when. the stretch is preparedfor westbound trailic, that is, from right to left, coded energy issupplied to the left-hand end of section 5T, and when the stretch isprepared for eastbound traffic, that is, from left to right, codedenergy is supplied to the right-hand end of sec- ...tion.

tion 6T. The coded energy supplied to'the rails of sections T-and 5T isof 75 or 180 code frequency according as the section in advance. is

occupied. or unoccupied. The equipment at the .signal location includesmeans, not shown,. effective when trafiic is established in onedirection or the other to supply energy of 75 or 180 code frequencytoone orthe other of the coding relays SECTM or GWCTM and thus causecoded energy to besupplied to the rails of one or the other of thesections 5T or 6T.

.Theequipment is shown in thecondition which :it assumes when trafiic-isnotestab-lished in either direction. At such times the relaysare allreleased and red lamps of the wayside signals 5WS and BES arelighted.

The first track relay GETR has a first movable contact 2 I and a secondmovable contact 22 which are connected by, a first supply conductor- I9.The second track relay 5WTR has a first movable contact 25 and a secondmovable contact 24 which ;are connected by a second supply conductor 25.

The contacts of the track relays BETR and SWTR.

are biased to a first or released position and are movable therefrom toa second or picked-up posi- -When the stretch is prepared for eastboundtraiiic, the first track relay EETR is operated by coded energysup-plied over the rails of section GT, and the second relay 5WTR isdeerengized so that its contacts remain released. When ,the

contacts of relay EETR, pick up, energy is supplied to the firstauxiliary relay BEFSA over the circuit which is traced from the secondor posi- .tive.terminal of the battery over front con- ,tact2l of relayGETR, the first supply conductor l9, front contact 22 of relay BETR,Winding of relay GEFSA, back contact 23 of relay BWFSA, .back contact 24of relay SWTR, the second supply conductor 26, and back contact 25 ofrelay 5WTR to the negative or second terminal of the battery 20. Theenergy supplied to the winding of relay GE'FSA picks up the relaycontacts with the result that during the released periods of thecontacts of relayfiETR energy is supplied to relay BSA over-thecircuitwhich is traced from the positive'terrninal of the battery 20through the windingof relay BSA, front contact 21 of relay I BEFSA, backcontact 22 of relay GETR, wire I9,

and back contact 2| of relay GETR to the negative terminal of thebattery 20,. Accordingly, the contacts of relay BSA pick up and itscontact connects the Winding of code following relay TM in multiple withthe winding of relay BSA so that, J during the release periods of relayGETR, relay TM is energized from battery 20 over the circuit lust tracedfor relay BSA and the contact of relay TM picks up.

, During subsequent picked-up periods of the relaylfiETR, energy issuppl ed to relay BEFSA. over the circuit traced of energy to relaysBSAand TM is interrupted above, and the supply and relay TM releases.The relays GEFSA and BSA areof a type the contacts of which are slow torelease so that they remain picked up during code following operation ofthe relays BETR and TM and contact 30 of relay BSA maintains the circuitof relay TM. l An asymmetric unit or rectifier is connected in serieswith the winding of relay TM and is poled. to permit energy from thebattery 20 to energize the relay TM but to prevent the supply to relayTM of the energy induced in the winding of relay BSA on interruption ofthe supply cfenergy to the relay winding. If this energy.

were supplied to relay TM, it would hasten release .of the relay.contact and might objectionably reduce the length of the picked-upperiods of this contact. v

When relay BSA picks up, its contact 3! establishes the circuit governedby the contact of relay TM for supplying energy from a source of directcurrent, not shown, the terminals of which are designated B and C in thedrawing, to the primary winding of the decoding transformer DT, from thesecondary winding of which energy is supplied through a resonantrectifier unit itODU to relay D to pick up the contacts of relay D whenand only when the relay TM is operated by energy of code frequency.

When relays BSA and GEFSA pick up, energy is supplied to the yellow lampY or to the green lamp G of signal 'BES according as contact 32 of relayD is released or picked up. In addition, when relay BSA picks up, energyis supplied over its contact 34 and. back contact 35' of relay 'EVVFSAto the red lamp R of Signal 5WS.

During occupancy of section ET the relay SE IR. remains released anddoes not establish the circuit of relay SEFSA so that it remainsreleased and does not establish the circuit of relay BSA. Accordingly,relay BSA is released and interrupts the supply of energy to thedecoding transformer DI and to the lamps Y and G of the signal BES, andestablishes circuits to maintain the supply of energ to the red lamps Rof signals SES- and 5WS.

When section ST is vacated, the relayfiETR is operated by coded energyand relays GEFSA and BSA are again picked up.

When the stretch is prepared for westbound traffic, the relay SWTR isoperated by coded energy supplied over the rails of section 5T so thatduring picked-up periods of the relay energy is supplied to relay 5WFSAover the circuit which is traced from the positive terminal of battery20 over front contact 25 of relay EWTR, wire 26, front contact '24 ofrelay SWFSA, back contact 27 of relay GEFSA, and back contacts 22 and 2!of relay BETR to the negative terminal of battery 2@. During thereleased periods of the relay SWTR energy is supplied to relay BSA overthe circuit which is traced from the positive terminal of battery 20-through the winding of relay BSA, front contact 23 of relay 5WSA, andback contacts 24 and 25 of relay SWTR. tothe negative terminal of thebattery, Accordingly, contact 3B of relay BSA is picked up to connectrelay TM in multiple with relay BSA While other contacts of relay BSAestabilsh the circuits of the decoding transformer and of the lamps Yand G of the signal 5WS, and signal 5WS displays a yellow or a greenindication depending on whether relay D is released or picked up, whilesignal GE'S displays its red indication.

When section 5T is occupied, the relay SWTR' remains released so thatrelays 5WFSA and BSA are released, and energy is supplied to the redlamps of the signals GES and 5WS.

The equipment shown in Fig. 2 is arranged so that overlapping of thecontacts on either of the track relays BETH and 5W'I'R. will not resultin improper display-of a permissive indication by either of the signals.

If movable contact 2| of relay 6ETR simultaneously engages its front andback points of contact, the battery 29 will be short circuited andenergy will not be supplied therefrom to relay GEFSA or to relay BSA andrelay BSA is certain to remain released. Similarly, if movable contact 725 of relay WTR simultaneously engages its front and back points ofcontact, the battery 20 will be short circuits and relays 5WFSA, TM andBSA will remain released and signals BES and 5W8 will both display theirstop indications.

If movable contact 22 of relay GETR simul taneously engages its frontand back points of contact, and if at the same time contact 2| engagesits front point of contact, energy will be supplied to relay SEFSA overthe circuit which is traced from the positive terminal of the battery 20over contacts 2| and 22 of relay BETH, winding of relay SEFSA, backcontact 23 of relay 5WFSA, and back contacts 24 and 25 of relay 5WTR tothe negative terminal of the battery. The energy supplied to relay GEFSApicks up its contacts so that its contact 21 interrupts the circuit ofrelay SWFSA and insures that it remains released, while, when contact 21of relay GEFSA is picked up, the relay BSA is short circuited over thecircuit which is traced from the right-hand terminal of the relaywinding over front contact 2| of relay BETR, wire 19, back contact 22 ofrelay GETR, and front contact 21 of relay SEFSA to the left-handterminal of the winding of relay BSA. Accordingly, relay BSA remainsreleased to cause signals GES and 5W8 to both display stop indicationsand does not establish circuits to permit signal BES or 5WS to display apermissive indication.

If contact 22 of relay BETR simultaneously engages its front and itsback points of contact, and if at the same time contact 2| engages itsback point of contact, the relay GEFSA will be shunted over the circuitwhich is traced from the left-hand terminal of the relay winding overback contact 23 of relay 5WFSA, back contacts 24 and 25 of relay 5WTR,back contact 2| of relay SETH, wire l9, and front contact 22 of relayGE'TR to the right-hand terminal of the winding of relay BEFSA. As therelay BEFSA is shunted, its contacts remain released and do notestablish the circuit of relay BSA so that it remains released.

Similarly, if movable contact 24 of relay BW'IR simultaneously engagesits front and back points of contact, the relay BSA will be shortcircuited if contacts 25 engages its front point of contact, and relaySWFSA will be short circuited if contact 25 engages its back .point ofcontact. In either case relay BSA remains released and maintains thecircuits for the red lamps of signals 5W8 and BES.

Although I have herein illustrated and described only two forms of codedetecting means embodying my invention, it is understood that variouschanges and modifications may be made therein within the scope of theappended claims without departing from the spirit and scope of myinvention.

Having thus described my invention, what I claim is:

1. In combination, a code following relay having two movable contactsactuated between a first and a second position substantially insynchronism, a source of current having a first and a second terminal, afirst slow releasing auxiliary relay having one terminal of its windingconnected to the first terminal of said source, a circuit including saidcode following relay contacts in series for connecting the otherterminal of the winding of said first auxiliary relay to the secondterminal of said source of current when said code following relaycontacts are both in their second position, a second auxiliar relayhaving one terminal of its winding connected to the second terminal ofsaid source, circuit means including in series a front contact of saidfirst auxiliary relay and said code following relay contacts forconnecting the other terminal of the winding of said second auxiliaryrelay to the first terminal of said source when said code followingrelay contacts are both in their first position, and a control circuitgoverned by a contact of said second auxiliary relay.

2. In combination, a code following relay having a first and a secondmovable contact which are actuated between a first and a second positionsubstantially in synchronism, a source of current having a first and asecond terminal, the first contact of said code following relay beingeffective according as it is in its first or its second position toconnect a supply conductor to the first or the second terminal of saidsource,'the second contact of said code following relay being effectivewhen in its first position provided the first contact of said codefollowing relay is also in its first position to establish a circuitincluding said supply conductor for supplying energy from said source toa first slow releasing auxiliary relay, said second contact of said codefollowing relay being effective when in its second position provided thefirst contact of said code following relay is also in its secondposition to establish a circuit including said supply conductor and afront contact of said first auxiliary relay for supplying energy fromsaid source to a second auxiliary relay, and a control circuit governedby said second auxiliary relay.

3. In combination, a code following relay having a first and a secondmovable contact which are actuated between a first and a second positionsubstantially in synchronism, a source of current having a first and asecond terminal, the first contact of said code following relay beingeffective according as it is in its first or its second position toconnect a supply conductor to the first or the second terminal of saidsource, a first slow releasing auxiliary relay having one terminal ofits Winding connected to the first terminal of said source, the secondcontact of said code following relay being effective when in its secondposition to connect said supply conductor to the other terminal of thewinding of said first auxiliary rela said second contact of said codefollowing relay being effective when in its first position provided thecontacts of said first auxiliary relay are picked up to connect saidsupply conductor to the second terminal of said source in series withthe winding of a second auxiliary relay, and a control circuit governedby a contact of said second auxiliary relay.

4. In combination, a code following relay having a first and a secondmovable contact which are actuated between a first and a second positionsubstantially in synchronism, a source of current having a first and asecond terminal, the first contact of said code following relay beingeifective according as it is in its first or its second position toconnect a supply conductor to the first or the second terminal of saidsource, the second contact of said code following relay being effectivewhen in its second position to connect said supply conductor to thefirst terminal of said source in series with the winding of a first slowreleasing auxiliary relay, said second contact of said code followingrelay being effective when in its first position provided the contactsof said first auxiliary relay are picked up to connect said supplyconductor to the second terminal of said source in series with thewinding of a second auxiliary relay, and a control circuit governed by acontact of said second auxiliary relay.

5. In a coded signaling system, in combination, a first and a secondcode following relay each of which is provided with a first and a secondmovable contact which are biased to a first position, means for at timesactuating the contacts of said first code following relay between theirfirst and a second position and for at other times actuating thecontacts of said second code following relay between their first and asecond position, the first contact of the first code following relaybeing effective according as it is in its first or its second positionto connect a first supply conductor to the first or the second terminalof a source of current, the first contact of the second code followingrelay being eifective according as it is in its first or its secondposition to connect a second supply conductor to the first or the secondterminal of said source of current, the second contact of said firstcode following relay being effective when in its second position toconnect said first upply conductor to the first terminal of said sourcein series with the winding of a first slow releasing auxiliary relayprovided the contacts of a second slow releasing auxiliary relay arereleased and the contacts of said second code following relay are intheir first position, the second contact of said first code followingrelay being effective when in its first position to connect said firstsupply conductor to the second terminal of said source in series withthe winding of a third auxiliary relay provided the contacts of saidfirst auxiliary relay are picked up, the second contact of said secondcode following relay being effective when in its second position toconnect said second supply conductor to the first terminal of saidsource in series with the winding of said second auxiliary relayprovided the contacts of said first auxiliary relay are released andcontacts of said first code following relay are in their first position,the second contact of said second code following relay being effectivewhen in its first position to connect said second supply conductor tothe second terminal of said source in series with the winding of saidthird auxiliary relay provided the contacts of said second auxiliaryrelay are picked up, a circuit governed by said first and thirdauxiliary relays, and a circuit governed by said second and thirdauxiliary relays.

6. In a coded signaling system, in combination, a first and a secondcode following relay each of which is provided with a first and a secondmovable contact which are biased to a first position, means for at timesactuating the contacts of said first code following relay between theirfirst and a second position and for at other times actuating thecontacts of said second code following relay between their first and asecond position, the first contact of the first code following relaybeing effective according as it is in its first or its second positionto connect a first supply conductor to the first or the second terminalof a source of current, the first contact of the second code followingrelay being effective according as it is its first or its secondposition to connect a second supply conductor to the first or the secondterminal of said source of current, the second contact of said firstcode following relay being effective when in its second position toconnect said first supply conductor to the first terminal of said sourcein series with the winding of a first slow releasing auxiliary relayprovided the contacts of a second slow r leasing auxiliary relay arereleased, the second contact of said first code following relay beingeffective when in its first position to connect said first supplyconductor to the second terminal of said source in series with thewinding of a third auxiliary relay provided the contacts of said firstauxiliary relay are picked up, the second contact of said second codefollowing relay being effective when in its second position to connectsaid second supply conductor to the first terminal of said source inseries with the winding of said second auxiliary relay provided thecontacts of said first auxiliary relay are released, the second contactof said second code following relay being effective when in its firstposition to connect said second supply conductor to the second terminalof said source in series with the winding of said third auxiliary relayprovided the contacts of said second auxiliary relay are picked up, acircuit governed by said first and third auxiliary relays, and a circuitgoverned by said second and third auxiliary relays.

FRANK H. NICHOLSON.

